On-line advertisements (or “ads”) allow advertisers to reach a wide range of viewers through the Internet. Ads can be played as part of video programs. The video program and the ad can be, for example, Flash videos that comply with Flash video standards promoted by Adobe Corporation, San Jose, Calif. Code for playing the video program and the ad can be in the format of SWF files that can be executed by a Flash player, such as Adobe Flash Player.
The Flash Player has security features based on sandboxes, which are logical security groupings that are used to contain resources. The security sandboxes define the range of data and operations that each Flash application may access. The Flash Player assigns SWF files to sandboxes based on their origin, and sandbox boundaries are determined by Internet domains or, for local SWF files, on the class of the local SWF file. The Flash Player runs SWF files from the Internet in separate sandboxes that correspond to their origin domains. Two SWF files that run in the same sandbox (for example, two SWF files downloaded from the same network domain) may interact with each other. SWF files may also interact with SWF files from other sandboxes in accordance with specific security rules and configuration settings.